Caltracs question

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crackedback said:
I agree.

The set up is soft in the first 330. It's basically .1+ off at 60' and .2 off at 330/660
Converter, tires, ignition timing, chassis, launch methods all come into play.
It's not lacking power as it's running out the back strong. :thumbsup:
Picking up 22 MPH in the back half compared to most cars at 87 picking up about 20 mph.
Click to expand...


Thanks for all the feedback guys! I really appreciate it. New tires and spool it is! I will also be taking a video of the launch to provide more info ... sucks I have to wait until spring :(

other info you mentioned:
converter = 10" TCI (I think it's their street fighter) w/ 3200 stall
timing = distributor is locked all in @ 34*
chassis = all steering/suspension is new including all bushings, etc; subframe connectors welded in
launching @ 2500RPM off the two step
93 pump gas
 
I think you'll find good improvement with your new tyres etc., and go in the 3's, just as a comparison, this was my old 10.1CR 360hp 340ci 727 street/strip car back in the 80's, all steel, 3500lbs....4.30's/4200 TA verter 10x28's on stock springs clamped at the front w/snubber, long shocks, [email protected], 1.73 60...with a best of 12.39 NA

0cuda_launch_663.jpg
 
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Hot Metal said:
I think you'll find good improvement with your new tyres etc., and go in the 3's, just as a comparison, this was my old 10.1CR 360hp 340ci 727 street/strip car back in the 80's, all steel, 3500lbs....4.30's/4200 TA verter 10x28's on stock springs clamped at the front w/snubber, long shocks, [email protected], 1.73 60...with a best of 12.39 NA
Click to expand...

That's some motivation right there! Awesome!

When you say long shocks, I'm assuming you're referring to the front end? What torsion bars?
 
No front end was stock, no's matching car, shocks were loose (worn), front end would rise easy but controlled not snap up. Can't remember exactly what rear shocks but we put the DC extensions on them for more travel. I think the bump stop for A-arm was off or worn down on pass side as would've lifted both wheels, not what I was trying to do, just a by product of some good Torque from that motor./verter combo...stock 2.02 heads, no porting.....had long race hdrs, modded 850DP w/50cc fr pump and sft cam, Holley SD intake+ 2" open spacer......36 deg total, max revs 6200.
 
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mderoy340 said:
What rear gear?
What first gear ratio?
What carb?
What size rear tire?
Click to expand...
any of you guys ever thot about drilling a very small hole in the front shocks, letting the fluid out, to get faster front end rise ? not for a Street car, but a cheap trick that worked (HELPED) on a 10.40 car yrs ago.
 
Like others have said I think new tires are going to help your 60ft a lot. Here is a picture of my Dart launching last Saturday. This is with brand new MT ET streets. This run was 12.39 @ 107 with a 1.70 60 ft time. You are making more horsepower than me because of your 109 MPH. Once you get your 60ft dialed in you should see some faster times than this 12.39. Have you checked to make sure you have 5 inches of front end travel?

image.jpg
 
mderoy340 said:
What rear gear?
What first gear ratio?
What carb?
What size rear tire?
Click to expand...

If your asking me?...
4.30 gears, std posi
std 1st 727 ratio, we built the box with 4.2 lever, full manual, drilled + 4 holes in drum, shifted mega hard, std pattern to use stock slapstick shifter.
old 850 d/pumper Holley 2 idle screws, choke tower milled off, no rear PV, 50cc front pump, extended shooters, 2.5PV etc etc.
Good year Eagle 10x28" slicks.
 
Hot Metal said:
If your asking me?...
4.30 gears, std posi
std 1st 727 ratio, we built the box with 4.2 lever, full manual, drilled + 4 holes in drum, shifted mega hard, std pattern to use stock slapstick shifter.
old 850 d/pumper Holley 2 idle screws, choke tower milled off, no rear PV, 50cc front pump, extended shooters, 2.5PV etc etc.
Good year Eagle 10x28" slicks.
Click to expand...
No. Asking OP
 
famous bob said:
any of you guys ever thot about drilling a very small hole in the front shocks, letting the fluid out, to get faster front end rise ? not for a Street car, but a cheap trick that worked (HELPED) on a 10.40 car yrs ago.
Click to expand...
Just remember to make sure they're NOT! GAS CHARGED SHOCKS before you go to drilling.
 
famous bob said:
any of you guys ever thot about drilling a very small hole in the front shocks, letting the fluid out, to get faster front end rise ? not for a Street car, but a cheap trick that worked (HELPED) on a 10.40 car yrs ago.
Click to expand...


That was before you could buy a reasonable shock.

Guys spend big $$$$$$$$$$$$$ on everything but shocks. The Viking double adjustable shock is a bolt on deal. The QA-1 is similar. When you can buy a bolt on, double adjustable shock for about $170.00 each...why not??? Then you will have the ability to TUNE the shock.
 
........I have the Viking double adjustable rear shocks...They are great when tuning the rear suspension cause they control compression and rebound........I think mine have 9 adjustments either way....kim......
 
oldkimmer said:
........I have the Viking double adjustable rear shocks...They are great when tuning the rear suspension cause they control compression and rebound........I think mine have 9 adjustments either way....kim......
Click to expand...


You should have 19 clicks on each. So 19 for bump and 19 for rebound. That is a total of 361 different possibilities. Pretty cool deal for not a lot of money.

Now you need to get them on the front. You'd be surprised how much you can find just tuning the front.
 
mderoy340 said:
What rear gear?
What first gear ratio?
What carb?
What size rear tire?
Click to expand...

3:73 rear
Standard 727 (I should know this but don't)
750 Holley mechanical
26 dia MT actually 235/60-15

Walker434 said:
Like others have said I think new tires are going to help your 60ft a lot. Here is a picture of my Dart launching last Saturday. This is with brand new MT ET streets. This run was 12.39 @ 107 with a 1.70 60 ft time. You are making more horsepower than me because of your 109 MPH. Once you get your 60ft dialed in you should see some faster times than this 12.39. Have you checked to make sure you have 5 inches of front end travel?
Click to expand...

I did take a peak under the front end today but didn't take any measurements, on the to do list
 
Walker434 said:
Have you checked to make sure you have 5 inches of front end travel?
Click to expand...

What exactly am I measuring? Frame travel or suspension? If suspension, what measurement? shocks, spindle? Where is the 5" derived from? I assume the 1st measurement is at ride height?
 
Car on level ground. Measure from ground to fender lip vertical through spindle centerline.

Jack car up under K frame try to keep it level and when the wheel lifts off the ground, take the same measurement as when static. Subtract and you have your number.
 
crackedback said:
Car on level ground. Measure from ground to fender lip vertical through spindle centerline.

Jack car up under K frame try to keep it level and when the wheel lifts off the ground, take the same measurement as when static. Subtract and you have your number.
Click to expand...

Now that's a thorough response! Thank you!
 
chillent said:
3:73 rear
Standard 727 (I should know this but don't)
750 Holley mechanical
26 dia MT actually 235/60-15



I did take a peak under the front end today but didn't take any measurements, on the to do list
Click to expand...

My car is very close to your setup and I had the same problem. As the tune put out more power, traction issues started. I was using cheap Monroe gas shocks front and rear, Mancini 1981/1982 rear springs (same as MP A body SS springs, stock 340 T bars, front end is all MOOG rubber, welded frame connectors, adjustable snubber 1" from floor pan, MT ET Street Drag radial 27" 255/60/15 19 PSI, 3.91 gear, stock fuel tank, battery in trunk passenger side.
Car would hook, unload and spin, then hook again.

Car is driven 50 miles to the track, tires deflated to 19 PSI, snubber set to 1/4", and cutouts opened.
60' is now a consistent 1.65/1.66 @ 1800 rpm launch, 1.62 @ 2400.
- Cut upper control arm rubber bumpers to 1/2" and left the lower bump stops stock. (I like my front wheels on the track for better control)
- Installed Summit 3 way front drag shocks set to 90/10
- Installed Competition Engineering rear drag shocks set to 50/50
- Modified adjustable snubber to sit 1/4" from floor pan at race height, (driver and fuel level for race). Snubber is a simple pin for up and down settings.
- Both rear spring front sections are clamped and one clamp is used in the rear section.

I'm a budget old school racer with a high 11 low 12 second street/strip car. The 3 way drag shocks worked for my car and are not expensive. Before you spend money on shocks let the suspension hang and measure the max extension you need.
 
mderoy340 said:
My car is very close to your setup and I had the same problem. As the tune put out more power, traction issues started. I was using cheap Monroe gas shocks front and rear, Mancini 1981/1982 rear springs (same as MP A body SS springs, stock 340 T bars, front end is all MOOG rubber, welded frame connectors, adjustable snubber 1" from floor pan, MT ET Street Drag radial 27" 255/60/15 19 PSI, 3.91 gear, stock fuel tank, battery in trunk passenger side.
Car would hook, unload and spin, then hook again.

Car is driven 50 miles to the track, tires deflated to 19 PSI, snubber set to 1/4", and cutouts opened.
60' is now a consistent 1.65/1.66 @ 1800 rpm launch, 1.62 @ 2400.
- Cut upper control arm rubber bumpers to 1/2" and left the lower bump stops stock. (I like my front wheels on the track for better control)
- Installed Summit 3 way front drag shocks set to 90/10
- Installed Competition Engineering rear drag shocks set to 50/50
- Modified adjustable snubber to sit 1/4" from floor pan at race height, (driver and fuel level for race). Snubber is a simple pin for up and down settings.
- Both rear spring front sections are clamped and one clamp is used in the rear section.

I'm a budget old school racer with a high 11 low 12 second street/strip car. The 3 way drag shocks worked for my car and are not expensive. Before you spend money on shocks let the suspension hang and measure the max extension you need.
Click to expand...
-------Any of you guys have any trouble w/ a caltrac spring letting ur car set unlevel? mine is down on the drivers side about 2" setting still. sucks!
 
You probably have too much preload on the passenger side. I had that same issue and let off the preload and it leveled back up.
 
crackedback said:
Car on level ground. Measure from ground to fender lip vertical through spindle centerline.

Jack car up under K frame try to keep it level and when the wheel lifts off the ground, take the same measurement as when static. Subtract and you have your number.
Click to expand...

mderoy340 said:
I'm a budget old school racer with a high 11 low 12 second street/strip car. The 3 way drag shocks worked for my car and are not expensive. Before you spend money on shocks let the suspension hang and measure the max extension you need.
Click to expand...

Finally measured the front suspension travel yesterday ... 3" where it stops on the UCA bumper ... so, totally remove the bumper or modify?
 
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